The objective of this project is to create and manage a comprehensive dataset of groups and movements that have usedterrorist tactics within the United States

–

at some point between 1970 and 2007

–

to achieve political, religious, social oreconomic goals. These data will be integrated into the Terrorist and Extremist Violence in the United States (TEVUS)database in the near future as part of the larger Integrating U.S. Security Databases (IUSSD) project.START obtained data on terrorist groups and other groups involved in extremist movements in March 2008 from theTerrorism Knowledge Base (TKB), a project managed by the Memorial Institute for the Prevention of Terrorism (MIPT).

However, after vetting MIPT’s profiles, concerns about the reliability a

nd validity of these data soon mounted as many of

the profiles proved to lack verifiable sources. Attempts to reconcile MIPT’s group

-

level data with START’s Global

Terrorism Database (GTD) also unearthed several gaps and inconsistencies: for instance, compared with the GTD, theTKB contained 80 fewer extremist groups that have attacked in the United States (including Puerto Rico) since 1970. Inaddition, there were no clear inclusion criteria for which actors appeared within the MIPT database. As such, STARTmade the decision to launch a new data collection effort, focused only on groups that had been active in the United States.

A group or movement is included in the PPT-US if it is identified in the Global Terrorism Database ashaving launched at least one terrorist attack against targets within the United States homeland. PPT-US only includes groups that have at least one incident for which there is no reservation, in the eyesof GTD analysts, that the incident in question is truly terrorism (as opposed to non-terrorist violence orcrime)

and

for which there is high confidence that the accused group is in fact responsible for theattack.

DEFINITION OF TERRORISM

The GTD

defines terrorism as “

the threatened or actual use of illegal force and violence by a non-state actor to attain a political, economic, religious, or social goal through fear, coercion orintimidation

.”

This definition is operationalized using the following criteria.Mandatory Criteria:1.

The incident must be intentional

–

the result of a conscious calculation on the part of aperpetrator.2.

The incident must entail some level of violence or threat of violence

-includingproperty violence, as well as violence against people.3.

The perpetrators of the incidents must by sub-national actors.

This database does notinclude acts of state terrorism.In addition,

at least two

of the following three

criteria must be present:

Criterion 1:

The act must be aimed at attaining a political, economic, religious, or socialgoal

. In terms of economic goals, the exclusive pursuit of profit does not satisfy this criterion. Itmust involve the pursuit of more profound, systemic economic change.

Criterion 2:

There must be evidence of an intention to coerce, intimidate, or conveysome other message to a larger audience (or audiences) than the immediate victims

. Itis the act taken as a totality that is considered, irrespective if every individual involved incarrying out the act was aware of this intention. As long as any of the planners or decision-

: The action must be outside the context of legitimate warfare activities

. Thatis, the act must be outside the parameters permitted by international humanitarian law(particularly the prohibition against deliberately targeting civilians or non-combatants).

CONFIDENCE CRITERIA

1 = Source(s) for this variable are known to possesses inherent bias or consistent errors in reporting,but also has a record of providing some accurate information.2 = The base confidence value. Information informing this coding is from highly credible source(s);source(s) have general reputation for unbiased coverage, thorough corroboration and factualaccuracy. No specific knowledge about the validity of this particular information.3 = Very high confidence in the validity and reliability of the information informing the coding of thisvariable.

NOTE

Each variable has a corresponding information source. Citing the information source(s) for eachvariable allows users of the data to reference original source material so that they can determinewhether they agree with how each variable is coded, providing users the opportunity to have higherlevels of confidence regarding how they use and interpret the data.